Changing CW&P ratio

[clive]

My Ford 302 with Holly Street Avenger carb is never happy under 60 mph in top gear and actually uses more fuel when in fifth gear than fourth at those speeds as the secondaries are never fully open. I only use fifth for motorway cruising which isn't very often up here.

[StuBaker]

Hi Clive, do you know your diff ratio?
And gearbox?
Cheers,
StuB

[clive]

No idea!

[StewbieC]

T5 (0.68 5th)and 3.54 diff doesn't like 5the below 55. Like Clive I drive in 4th up to 60 and tend to just use 5th as an overdrive for cruising on dual carriageways and motorways.

[peterc]

I thought that the 302 had a lot more torque than the Rover.
I run a 3.3 diff and don’t have issues of cruising in 5th on 2 lane roads.
When mine is running again I will have to note what revs at 50.
Peter C

[peterc]

By calculation I recon that’s around 1600 rpm at 50 for my engine. It will pull quite happily for in traffic style driving. Of course if you want to gallop then it’s down to 4th or even 3rd if you really want to give it the beans.
Peter C

[clive]

The Ford does have loads of torque (290lb ft if I remember) and will quite happily sit at 40 mph in top gear, however it is far from economic at such low revs.

[peterc]

Interesting. Perhaps I should be using more revs in future.
Peter C

[clive]

Interesting. Perhaps I should be using more revs in future.
Peter C

Definitely. It does sound better!

[peterc]

I don’t like being noisy like the guy down the road with a V10 Audi R8 with a sports exhaust. Unnecessarily vocal in my opinion but then perhaps I’m just getting a bit old. Time and place and all that.
Peter C